Foldable display device with movable support body

ABSTRACT

A foldable display device includes a first casing and a second casing supporting a first area and a second area of a display panel, respectively, a support disposed between the first casing and the second casing, supporting the display panel based on the folding direction of the foldable display device, and including a support body which ascends toward the display panel during the out-folding operation, and descends toward a bottom face of the hinge cover during the in-folding operation.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims a priority benefit under 35 U.S.C. § 119(a) ofKorean Patent Application No. 10-2020-0164381 filed in the Republic ofKorea on Nov. 30, 2020, which is hereby incorporated by reference in itsentirety and for all purposes as if fully set forth herein.

BACKGROUND Technical Field

The present disclosure relates to a foldable display device, and, moreparticularly, to a foldable display device that can be folded both in anin-foldable manner and an out-foldable manner.

Description of Related Art

Recently, portable terminals, such as wireless terminals, PersonalDigital Assistants (PDA), Portable Multimedia Players (PMPs), andelectronic notebooks have become smaller in size for convenience inportability. However, since a user wants to receive various information,such as text information, a moving image, a still image, an MP3, a game,etc., on a screen of a portable terminal, there is an increasing demandfor increase the screen size.

In order to enlargen the screen while maintaining the portability of theportable terminal, development of a foldable display device using aflexible display panel that can be bent or folded is in progress. Thisfoldable display device can be applied not only to mobile devices suchas mobile phones, electronic books, and electronic newspapers, but alsoto various fields, such as televisions and monitors, but is not limitedthereto.

SUMMARY OF THE DISCLOSURE

A conventional foldable display device is implemented only in anin-foldable manner in which the device is folded such that foldeddisplay panel portions face toward each other, or only an out-foldablemanner in which the device is folded such that folded display panelportions face outwardly (e.g., away from each other). However, there isa need for a foldable display device capable of implementing both anin-folding operation and an out-folding operation for variousapplications. Accordingly, the inventors of the present disclosure haveinvented a foldable display device that can be folded both in anin-foldable manner and an out-foldable manner.

Thus, a purpose of the present disclosure is to provide a foldabledisplay device that can be folded in both in an in-foldable manner andan out-foldable manner.

Purposes according to the present disclosure are not limited to theabove-mentioned purpose. Other purposes and advantages according to thepresent disclosure that are not mentioned can be understood based onfollowing descriptions, and can be more clearly understood based onembodiments according to the present disclosure. Further, it will beeasily understood that the purposes and advantages according to thepresent disclosure can be realized using means shown in the claims andcombinations thereof.

In order to achieve the above-described purpose, a foldable displaydevice according to an embodiment of the present disclosure includes adisplay panel having a first area, a second area, and a foldable areatherebetween, a first casing and a second casing supporting a first areaand a second area of a display panel, respectively, a support disposedbetween the first casing and the second casing, wherein the support isconstructed for selectively supporting the display panel based on thefolding direction, and a hinge cover for accommodating therein thesupport. The support includes a support body which ascends toward thedisplay panel during the out-folding operation, and descends toward abottom face of the hinge cover during the in-folding operation.Accordingly, the foldable display device according to an embodiment ofthe present disclosure can achieve the in-folding and out-foldingoperations.

A foldable display device according to another embodiment of the presentdisclosure includes a display panel having a foldable area; a firstcasing and a second casing to support the display panel, wherein thefirst casing and the second casing are coupled to each other via ahinge; a support coupled to the hinge to selectively support the displaypanel according to a folding direction of the foldable display device;and a hinge cover to accommodate therein the hinge and the support,wherein the support includes a support body, wherein the support bodyascends toward the display panel during an out-folding operation of thefoldable display device, and descends toward a bottom face of the hingecover during an in-folding operation of the foldable display device.

A foldable display device according to yet another embodiment of thepresent disclosure includes a first casing supporting a first area of adisplay panel; a second casing accommodating a slidable plate andincluding a sliding-guiding groove to guide a slide movement of theslidable plate, wherein the slidable plate supports a second area of thedisplay panel; a support disposed between the first casing and thesecond casing to selectively support the display panel according to afolding direction of the foldable display device; and a hinge cover toaccommodate the support therein; wherein the support includes a supportbody, wherein the support body ascends toward the display panel duringan out-folding operation of the foldable display device, and descendstoward a bottom face of the hinge cover during an in-folding operationof the foldable display device.

According to the present disclosure, the display device can include thesupport body that moves up and down according to the folding directionof the first casing and the second casing. Thus, the display device canbe capable of performing the in-folding and out-folding operations.

According to the present disclosure, the display device can include thesupport body that moves up and down according to the folding directionof the first casing and the second casing. Thus, the display panel canbe stably supported in the unfolded state and the out-folded state.

According to the present disclosure, a slidable plate can be movablycoupled to the second casing. Thus, in the out-folded state, stressapplied to the display panel can be reduced.

Effects of the present disclosure are not limited to the above-mentionedeffects, and other effects as not mentioned will be clearly understoodby those skilled in the art from following descriptions.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a side view of a foldable display device according to anembodiment of the present disclosure as viewed in an unfolded state.

FIG. 2 is a plan view of a foldable display device according to anembodiment of the present disclosure as viewed in an unfolded state.

FIG. 3 is a plan view showing a state in which a display panel isremoved while a foldable display device is unfolded according to anembodiment of the present disclosure.

FIG. 4 and FIG. 5 are plan views for illustrating a support of afoldable display device according to an embodiment of the presentdisclosure.

FIG. 6 is a perspective view showing a movable support body of afoldable display device according to an embodiment of the presentdisclosure.

FIG. 7 is a drawing to illustrate a support plate of a foldable displaydevice according to an embodiment of the present disclosure.

FIG. 8 is a side view of a foldable display device according to anembodiment of the present disclosure as viewed in an in-folded state.

FIG. 9 is a side view of a foldable display device according to anembodiment of the present disclosure as viewed in an out-folded state.

FIG. 10 is a perspective view for illustrating a support of a foldabledisplay device according to an embodiment of the present disclosure.

FIG. 11 is a perspective view showing a hinge cover of a foldabledisplay device according to an embodiment of the present disclosure.

DETAILED DESCRIPTION OF THE EMBODIMENTS

Advantages and features of the present disclosure, and a method ofachieving the Advantages and features will become apparent withreference to embodiments described later in detail together with theaccompanying drawings. However, the present disclosure is not limited tothe embodiments as disclosed below, but can be implemented in variousdifferent forms. Thus, these embodiments are set forth only to make thepresent disclosure complete, and to completely inform the scope of thedisclosure to those of ordinary skill in the technical field to whichthe present disclosure belongs, and the present disclosure is onlydefined by the scope of the claims.

A shape, a size, a ratio, an angle, a number, etc., disclosed in thedrawings for describing the embodiments of the present disclosure areexemplary, and the present disclosure is not limited thereto. The samereference numerals refer to the same elements herein. Further,descriptions and details of well-known steps and elements are omittedfor simplicity of the description. Furthermore, in the followingdetailed description of the present disclosure, numerous specificdetails are set forth in order to provide a thorough understanding ofthe present disclosure. However, it will be understood that the presentdisclosure can be practiced without these specific details. In otherinstances, well-known methods, procedures, components, and circuits havenot been described in detail so as not to unnecessarily obscure aspectsof the present disclosure.

The terminology used herein is for the purpose of describing particularembodiments only and is not intended to be limiting of the presentdisclosure. As used herein, the singular forms “a” and “an” are intendedto include the plural forms as well, unless the context clearlyindicates otherwise. It will be further understood that the terms“comprises,” “comprising,” “includes,” and “including” when used in thisspecification, specify the presence of the stated features, integers,operations, elements, and/or components, but do not preclude thepresence or addition of one or more other features, integers,operations, elements, components, and/or portions thereof. As usedherein, the term “and/or” includes any and all combinations of one ormore of the associated listed items. Expression such as “at least oneof” when preceding a list of elements can modify the entire list ofelements and can not modify the individual elements of the list. Ininterpretation of numerical values, an error or tolerance therein canoccur even when there is no explicit description thereof.

In addition, it will also be understood that when a first element orlayer is referred to as being present “on” a second element or layer,the first element can be disposed directly on the second element or canbe disposed indirectly on the second element with a third element orlayer being disposed between the first and second elements or layers. Itwill be understood that when an element or layer is referred to as being“connected to,” or “coupled to” another element or layer, it can bedirectly on, connected to, or coupled to the other element or layer, orone or more intervening elements or layers can be present. In addition,it will also be understood that when an element or layer is referred toas being “between” two elements or layers, it can be the only element orlayer between the two elements or layers, or one or more interveningelements or layers can also be present.

Further, as used herein, when a layer, film, region, plate, or the likeis disposed “on” or “on a top” of another layer, film, region, plate, orthe like, the former can directly contact the latter or still anotherlayer, film, region, plate, or the like can be disposed between theformer and the latter. As used herein, when a layer, film, region,plate, or the like is directly disposed “on” or “on a top” of anotherlayer, film, region, plate, or the like, the former directly contactsthe latter and still another layer, film, region, plate, or the like isnot disposed between the former and the latter. Further, as used herein,when a layer, film, region, plate, or the like is disposed “below” or“under” another layer, film, region, plate, or the like, the former candirectly contact the latter or still another layer, film, region, plate,or the like can be disposed between the former and the latter. As usedherein, when a layer, film, region, plate, or the like is directlydisposed “below” or “under” another layer, film, region, plate, or thelike, the former directly contacts the latter and still another layer,film, region, plate, or the like is not disposed between the former andthe latter.

In descriptions of temporal relationships, for example, temporalprecedent relationships between two events such as “after,” “subsequentto,” “before,” etc., another event can occur therebetween unless“directly after,” “directly subsequent” or “directly before” isindicated.

It will be understood that, although the terms “first,” “second,”“third,” and so on can be used herein to describe various elements,components, regions, layers and/or sections, these elements, components,regions, layers and/or sections should not be limited by these terms.These terms are used to distinguish one element, component, region,layer or section from another element, component, region, layer orsection. Thus, a first element, component, region, layer or sectiondescribed below could be termed a second element, component, region,layer or section, without departing from the spirit and scope of thepresent disclosure.

The features of the various embodiments of the present disclosure can bepartially or entirely combined with each other, and can be technicallyassociated with each other or operate with each other. The embodimentscan be implemented independently of each other and can be implementedtogether in an association relationship.

Unless otherwise defined, all terms including technical and scientificterms used herein have the same meaning as commonly understood by one ofordinary skill in the art to which this inventive concept belongs. Itwill be further understood that terms, such as those defined in commonlyused dictionaries, should be interpreted as having a meaning that isconsistent with their meaning in the context of the relevant art andwill not be interpreted in an idealized or overly formal sense unlessexpressly so defined herein.

Hereinafter, a foldable display device according to some embodiments ofthe present disclosure will be described.

FIG. 1 is a side view of a foldable display device according to anembodiment of the present disclosure as viewed in an unfolded state.FIG. 2 is a plan view of a foldable display device according to anembodiment of the present disclosure as viewed in an unfolded state.FIG. 3 is a plan view showing a state in which a display panel isremoved while a foldable display device is unfolded according to anembodiment of the present disclosure.

Referring to FIG. 1 , FIG. 2 and FIG. 3 , the foldable display deviceaccording to an embodiment of the present disclosure includes a firstcasing 101, a second casing 102, a support plate 120, a display panel130, a slidable plate 150, a support 160, a hinge cover 170, a firstpivoting plate 191 and a second pivoting plate 192.

The foldable display device includes the display panel 130 having afirst area 131, a second area 135 and a foldable area 133 therebetween,the first casing 101 supporting the first area 131 of the display panel130, the second casing 102 supporting the second area 135 of the displaypanel 130, the support 160 placed between the first casing and thesecond casing to selectively support the display panel 130 according toa folding direction, and the hinge cover 170 that accommodates thesupport 160 therein. The support 160 includes a support body 161 whichascends toward the display panel 130 during the out-folding operation,and descends toward a bottom face of the hinge cover 170 during thein-folding operation.

An entire area of the display panel 130 can be divided into the firstarea 131, the second area 135, and the foldable area 133. The first area131 can be defined as a partial area of the display panel 130 located onone side (e.g., a first side) of the foldable area 133. The second area135 can be defined as a partial area of the display panel 130 located onan opposite side (e.g., a second side opposite to the first side) of thefoldable area 133. When the display panel 130 is unfolded into a flatstate, the first area 131, the second area 135, and the foldable area133 constitute a single display area, thereby providing a wide screen.

The display panel 130 can be embodied as a flexible display panel usinga flexible substrate. In one example, the display panel 130 can includea flexible organic light-emitting display panel, a flexibleelectrophoretic display panel, a flexible liquid crystal display panel,or a flexible electro-wetting display panel.

The display panel 130 can include a flexible pixel array substratehaving an active matrix type pixel array, and an encapsulating memberprotecting the pixel array. The flexible pixel array substrate can bemade of a plastic material or can be made of a metal foil. For example,the plastic flexible pixel array substrate can be made of one selectedfrom polyimide (PI), polyethylene terephthalate (PET),polyethylenapthanate (PEN), polycarbonate (PC), polynorbornene (PNB),and polyethersulfone (PES). The pixel array includes a plurality ofpixels in each pixel area adjacent to each of intersections between aplurality of gate lines and a plurality of data lines. The pixelincludes a display element that displays an image corresponding to animage signal. In this connection, the display element can be embodied asan organic light-emitting element, a liquid crystal display element, anelectrophoretic element, or an electro-wetting display element. When thedisplay element is embodied as an organic light-emitting element or anelectrophoretic element, an encapsulating member according to oneexample can be formed on a flexible substrate to cover the pixel array,and can be embodied as a flexible encapsulating substrate or a flexibleencapsulation layer. When the display element is embodied as a liquidcrystal display element, an electro-wetting display element, or anelectrophoretic element, an encapsulating member according to anotherexample can be embodied as a flexible color filter substrate including acolor filter corresponding to a pixel.

Additionally, the display panel 130 can further include a polarizingfilm attached to the encapsulating member. However, the polarizing filmcan be omitted depending on an image rendering scheme of the displaypanel 130.

In one example, the foldable display device according to an embodimentof the present disclosure can be configured to further include a touchscreen for a user interface using a user's touch. The touch screen canbe attached to the display panel 130 or embedded in the display panel130 together with a pixel array.

The first area 131 of the display panel 130 is supported by the firstcasing 101 while the first area 131 of the display panel 130 is attachedto a partial area of the support plate 120 via a first adhesive member141, and a partial area of the support plate 120 is attached to thefirst casing 101 via a third adhesive member 143. The second area 135 ofthe display panel 130 is supported by the slidable plate 150 while thesecond area 135 of the display panel 130 is attached to a partial areaof the support plate 120 via a second adhesive member 142, and a partialarea of the support plate 120 is attached to the slidable plate 150 viaa fourth adhesive member 144. The slidable plate 150 is supported by thesecond casing 102. Thus, the second area 135 of the display panel 130 issupported by the second casing 102 via the slidable plate 150.

In an unfolded state of the foldable display device, the foldable area133 of the display panel 130 can be supported by the support 160, thefirst pivoting plate 191, and the second pivoting plate 192 via thesupport plate 120. The foldable area 133 of the display panel 130 maynot be attached to the support plate 120. This is intended to maintain afunction of supporting the display panel 130 while reducing a stressapplied to the display panel 130 during the in-folding and out-foldingoperations. The thinner the first adhesive member 141 and the secondadhesive member 142, a smaller a spacing between the foldable area 133of the display panel 130 and the support plate 120.

The foldable area 133 of the display panel 130 can be divided into acentral area and a first peripheral area and a second peripheral arearespectively arranged on both sides of the central area. The centralarea of the foldable area 133 of the display panel 130 can be supportedby the support body 161 of the support 160. The first peripheral area ofthe foldable area 133 of the display panel 130 can be supported by thefirst pivoting plate 191. The second peripheral area of the foldablearea 133 of the display panel 130 can be supported by the secondpivoting plate 192. In this connection, one end of the first pivotingplate 191 and one end of the second pivoting plate 192 can be supportedby the hinge cover 170. That is, the first pivoting plate 191 can besupported by a first side of the hinge cover 170 and the second pivotingplate 192 can be supported by a second side of the hinge cover 170opposite to the first side of the hinge cover 170. The first pivotingplate 191 and the second pivoting plate 192 are respectively arranged onboth sides of the support 160. The first pivoting plate 191 and thesecond pivoting plate 192 together with the support 160 can support thefoldable area 133 of the display panel 130.

Alternatively, in an embodiment of the present invention, the supportplate 120 can be omitted. Accordingly, the first area 131 of the displaypanel 130 is supported by the first casing 101 while the first area 131of the display panel 130 is directly attached to the first casing 101via the first adhesive member 141. The second area 135 of the displaypanel 130 is supported by the slidable plate 150 while the second area135 of the display panel 130 is attached to the slidable plate 150 viathe second adhesive member 142. The slidable plate 150 is supported bythe second casing 102. Thus, the second area 135 of the display panel130 is supported by the second casing 102 via the slidable plate 150. Inan unfolded state of the foldable display device, the foldable area 133of the display panel 130 can be supported by the support 160, the firstpivoting plate 191, and the second pivoting plate 192.

The first casing 101 can accommodate therein the first pivoting plate191. In this connection, an opposite end of the first pivoting plate 191opposite to one end of the first pivoting plate 191 supported by thehinge cover 170 can be pivotably coupled to an inner end area of thefirst casing 101 via a fastening member such as a pin. That is, a firstend of the first pivoting plate 191 can be connected to an inner area ofthe first casing 101 via a fastening member, and a second end of thefirst pivoting plate 191, opposite to the first end of the firstpivoting plate 191, can be supported by the hinge cover 170 (e.g., afirst end of the hinge cover 170). The first pivoting plate 191 canpivot inside the first casing 101 according to a pivoting motion of thefirst casing 101. The second casing 102 can accommodate the secondpivoting plate 192 therein. In this connection, an opposite end of thesecond pivoting plate 192 opposite to one end of the second pivotingplate 192 supported by the hinge cover 170 can be pivotably coupled toan inner end area of the second casing 102 via a fastening member suchas a pin. That is, a first end of the second pivoting plate 192 can beconnected to an inner area of the second casing 102 via a fasteningmember, and a second end of the second pivoting plate 192, opposite tothe first end of the second pivoting plate 192, can be supported by thehinge cover 170 (e.g., a second end of the hinge cover 170). The secondpivoting plate 192 can pivot inside the second casing 102 according to apivoting motion of the second casing 102. The inner end area of thefirst casing 101 can include a space to allow the first pivoting plate191 to pivot, while the inner end area of the second casing 102 caninclude a space to allow the second pivoting plate 192 to pivot. Thefirst casing 101 and second casing 102 can be folded or unfolded whilepivoting around the hinge cover 170. Each of the inner end area of thefirst casing 101 and the inner end area of the second casing 102 canrefer to an area adjacent to the hinge cover 170. When the foldabledisplay device is unfolded, the inner end area of the first casing 101and the inner end area of the second casing 102 can be disposed adjacentto each other. In this context, when the foldable display device isunfolded, an outer end area of the first casing 101 and an outer endarea of the second casing 102 can be far away from each other.

The second casing 102 can accommodate the slidable plate 150 therein andcan include a sliding-guiding groove 105 to guide a slide movement ofthe slidable plate 150. A plurality of slidable plates 150 can beprovided and a plurality of sliding-guiding grooves 105 can be provided.The slidable plate 150 can slide freely along a guide rail of thesliding-guiding groove 105 in a lateral direction, that is perpendicularto a vertical direction in which the support body 161 moves. Theslidable plate 150 can slide within the sliding-guiding groove 105 toreduce the stress applied to the foldable area 133 of the display panel130 during the out-folding operation.

The support 160 can further include three driving gears 163, 164, and165 that rotate while meshing with each other to lift up or lower downthe support body 161. The support body 161 can ascend or descendaccording to a rotation direction of one of the three driving gears 163,164, and 165. That is, the support body 161 includes a linear gear/rackgear that can directly engage the first driving gear 163, the firstdriving gear 163 directly engages the second driving gear 164, and thesecond driving gear 164 directly engages the third driving gear 165.Based on the unfolded state, the support body 161 ascends toward thedisplay panel 130 as the first driving gear 163 rotates in the clockwisedirection during the out-folding operation. During the in-foldingoperation, as the first driving gear 163 rotates in a counterclockwisedirection, the support body 161 descends toward the bottom face of thehinge cover 170. A detailed structure of the support body 161 will bedescribed later with reference to FIG. 6 .

FIG. 4 and FIG. 5 are plan views for illustrating a support of afoldable display device according to an embodiment of the presentdisclosure. FIG. 6 is a perspective view showing a support body of afoldable display device according to an embodiment of the presentdisclosure.

Referring to FIG. 4 and FIG. 5 , the support 160 can be coupled to thehinge 180. As previously described, the support 160 includes the supportbody 161, and the first to third driving gears 163, 164, and 165. Thehinge 180 includes a pair of hinge shafts 181, a first fixing plate 182,a pair of springs 183, a second fixing plate 184, hinge gears 185, athird fixing plate 186, a fourth fixing plate 187, and a pair ofpivoting plates 188. A combination of the support 160, the hinge cover170 and the hinge 180 can be referred to as a hinge assembly.

The first to third driving gears 163, 164, and 165 of the support 160can be disposed between the third fixing plate 186 and the fourth fixingplate 187 of the hinge 180. The third driving gear 165 is coupled to thehinge shaft 181 so that the third driving gear 165 can rotate in adirection corresponding to a rotation direction of the hinge shaft 181.The introduction of the second driving gear 164 can allow the firstdriving gear 163 to rotate in the same direction as that of the thirddriving gear 165. When the first casing 101 and the second casing 102are folded into an in-folded state, the hinge shaft 181 rotates in thecounterclockwise direction. Accordingly, the third driving gear 165 andthe first driving gear 163 rotates in the counterclockwise direction. Asthe first driving gear 163 rotates in a counterclockwise direction, thesupport body 161 descends in the downward direction, e.g., toward thebottom face of the hinge cover 170. Conversely, when the first casing101 and the second casing 102 are folded into an out-folded state, thehinge shaft 181 rotates in the clockwise direction. Accordingly, thethird driving gear 165 and the first driving gear 163 rotate in theclockwise direction. As the first driving gear 163 rotates in theclockwise direction, the support body 161 ascends in the upwarddirection, e.g., toward the display panel 130.

The spring 183 can be coupled to each hinge shaft 181 and can disposedbetween the first fixing plate 182 and the second fixing plate 184. Evenwhile the hinge gears 185 are rotating, the second fixing plate 184 canremain in close contact with the hinge gears 185 due to an elastic forceof the spring 183.

The second fixing plate 184 and the hinge gears 185 can be connected toeach other via a cam mechanism, and thus can allow a pivoted position ofthe first casing 101 and the second casing 102 to be maintained at apre-designed folding angle, for example, 0 degree (in-folded state), 30degrees, 60 degrees, 90 degrees, 120 degrees, 150 degrees, 180 degrees,210 degrees, 240 degrees, 270 degrees, 300 degrees, 330 degrees, and 360degrees (out-folded state).

The hinge gears 185 can include a pair of main hinge gears respectivelycoupled to a pair of hinge shafts 181. The hinge gears 185 can furtherinclude auxiliary hinge gears disposed between and engaged with the mainhinge gears.

A first fastener 1011 of the first casing 101 and a second fastener 1021of the second casing 102 can be coupled to a pair of fastening plates188 of the hinge 180, respectively. The fastening plate 188 can be fixedto the hinge shaft 181. Thus, the hinge shafts 181 rotate when the firstcasing 101 and second casing 102 are folded or unfolded. Furthermore,the first driving gear 163 can rotate by rotation of the hinge shaft 181when the first casing 101 and second casing 102 are folded or unfolded,where rotation of one of the hinge shafts 181 causes rotation of thethird driving gear 165, which causes rotation of the second driving gear164, and rotation of the second driving gear 164 causes rotation of thefirst driving gear 163.

Referring to FIG. 6 , one side wall of a lower portion of the supportbody 161 can have a rack gear 1615 meshing with an innermost of thethree driving gears 163, 164, and 165 within the hinge cover 170, thatis, the first driving gear 163. Two rack gears 1615 can be arranged andspaced from each other in a length direction of the side wall of a lowerportion of the support body 161. Since the support body 161 includes thetwo rack gears 1615 spaced apart from each other in the length directionof the side wall thereof, the support body 161 can ascend or descend ina right standing manner while not being inclined in the length direction(e.g., while maintaining a constant lateral position). The opposite sidewall of a lower portion of the support body 161 can have projections1614 respectively opposite to the rack gears 1615. When the support body161 ascends or descends, the projections 1614 of the support body 161can be guided by the hinge shaft 181 (see FIG. 5 ). The rack gears 1615on one side wall of a lower portion of the support body 161 can beguided by the first driving gear 163, while the projections 1614 on theopposite side wall of a lower portion of the support body 161 can beguided by the hinge shaft 181. Thus, the support body 161 can ascend ordescend while not being inclined in a width direction. The lower portionof the support body 161 can have grooves 1617 defined therein adjacentto the rack gears 1615, respectively. When the support 160 is coupled tothe hinge 180, the fourth fixing plate 187 can be fitted into the groove1617.

The support body 161 includes a lower portion 1613 having one side walland the opposite side wall, and an upper portion 1611 having a greaterwidth than that of the lower portion 1613. The upper portion 1611 of thesupport body 161 can have a top face as a convex curved surface towardthe display panel 130. When the top face of the upper portion 1611 ofthe support body 161 has a curved face, the top face can support thefoldable area 133 of the display panel 130 to maintain a predefinedcurvature thereof in the out-folded state of the device. The upperportion 1611 can have a length greater than that of the lower portion1613.

FIG. 7 is a drawing to illustrate a support plate of a foldable displaydevice according to an embodiment of the present disclosure.

Referring to FIG. 7 , the support plate 120 disposed between the displaypanel 130 and the first casing 101 and between the display panel 130 andthe second casing 102 can include a foldable portion 123 correspondingto (e.g., overlapping) the foldable area 133 of the display panel 130,and can made of a metal and a polymer material, and first and secondnon-foldable portions 121 and 125 respectively corresponding to (e.g.,overlapping) the first and second areas 131 and 135 of the display panel130 and can made of a metal material. The foldable portion 123 of thesupport plate 120 includes a first foldable portion 122 having aplurality of holes and can made of a metal material and a secondfoldable portion 124 that can made of a polymer material filling theplurality of holes.

The foldable portion 123 of the support plate 120 may not be attached tothe foldable area 133 of the display panel 130, while the first andsecond non-foldable portions 121 and 125 of the support plate 120 can berespectively attached to the bottom faces of the first and second areas131 and 135 of the display panel 130. This configuration is intended tomaintain a function of supporting the display panel 130 while reducingthe stress applied to the display panel 130 during the in-folding andout-folding operations.

FIG. 8 is a side view of a foldable display device according to anembodiment of the present disclosure as viewed in an in-folded state.

In the in-folded state, the foldable area 133 of the display panel 130is gently bent into a ‘Ω’ shape as received in a space created when thesupport body 161 descends toward the bottom face of the hinge cover 170and the first and second pivoting plates 191 and 192 pivot. The foldablearea 133 can contact the first and second pivoting plates 191 and 192and the support body 161 in the in-folded state. Distal ends of thefirst and second pivoting plates 191 and 192 can be respectively incontact with distal ends of the hinge cover 170, and can be placedbetween the distal ends of the hinge cover 170 and both edges of theupper portion of the support body 161 in the in-folded state.

FIG. 9 is a side view of a foldable display device according to anembodiment of the present disclosure as viewed in the out-folded state.

In the out-folded state, the foldable area 133 of the display panel 130can be folded in a state supported by the support body 161 as thesupport body 161 ascends towards the display panel 130. The top face ofthe support body 161 is formed as a predefined curved face, so that thefoldable area of the display panel 130 can be supported by the top faceof the support body 161 such that the predefined curvature of thefoldable area can be maintained. Therefore, the stress generated to thedisplay panel 130 due to the non-uniform curvature of the display panel130 can be minimized. The first and second pivoting plates 191 and 192can move along an outer surface of the hinge cover 170 while supportingthe display panel 130 in the out-folded state.

FIG. 10 is a perspective view for illustrating a support of a foldabledisplay device according to another embodiment of the presentdisclosure.

Referring to FIG. 10 , a support 160′ can further include an elasticplate 167 that is partially coupled to the upper portion 1611 of thesupport body 161. The elastic plate 167 has a flat shape during theunfolding operation, and is bent during the out-folding operation and incontact with the top face of the upper portion 1611. The elastic plate167 can support the foldable area 133 of the display panel 130 over awider area thereof in the unfolded state. During the out-foldingoperation, the foldable area 133 of the display panel 130 can besupported by the elastic plate 167 such that the predefined curvature ofthe foldable area is maintained. That is, during the out-foldingoperation, the elastic plate 167 is deformed against the upper portion1611 of the support body 161 such that the elastic plate 167 has aconvexly curved shape corresponding to the convexly curved shape of thetop surface of the upper portion 1611 of the support body 161.

FIG. 11 is a perspective view showing a hinge cover of a foldabledisplay device according to an embodiment of the present disclosure.

Referring to FIG. 11 , the hinge cover 170 includes a bottom face 175, apair of hinge shaft supports 171 that respectively extend verticallyfrom both sides in a length direction of the bottom face 175, and firstand second side curved portions 173 and 174 respectively on both sidesin a width direction of the bottom face 175. A middle portion of each ofthe first and second side portions 173 and 174 can be removed away sothat the first fastener 1011 of the first casing 101 and the secondfastener 1021 of the second casing 102 can be pivotally coupled to thefastening plates 188 of the hinge 180. The first and second sideportions 173 and 174 can be curved and thus can easily support thedistal ends of the first and second pivoting plates 191 and 192 duringthe unfolding and in-folding operations, or can allow the first andsecond pivoting plates 191 and 192 to easily move along the surfaces ofthe first and second side portions 173 and 174 during the out-foldingoperation.

An embodiment of the present disclosure can be described as follows.

A first aspect of the present disclosure provides a foldable displaydevice comprising: a display panel having a first area, a second area,and a foldable area therebetween; a first casing supporting the firstarea of the display panel; a second casing supporting the second area ofthe display panel; a support disposed between the first casing and thesecond casing to selectively support the display panel according to afolding direction of the foldable display device; and a hinge cover toaccommodate the support therein; wherein the support includes a supportbody, wherein the support body ascends toward the display panel duringan out-folding operation of the foldable display device, and descendstoward a bottom face of the hinge cover during an in-folding operationof the foldable display device.

In one implementation of the first aspect, the support further includesthree driving gears rotating in engagement with each other to lift up orlower down the support.

In one implementation of the first aspect, the support body has a lowerportion, wherein a rack gear is formed on one side wall of the lowerportion and meshes with one of the three driving gears.

In one implementation of the first aspect, the support body has a lowerportion and an upper portion having a greater width than a width of thelower portion, wherein the upper portion of the support has a top faceconvexly curved toward the display panel.

In one implementation of the first aspect, the support further includesan elastic plate partially coupled to the upper portion of the support,wherein the elastic plate has a flat shape during an unfolding operationof the foldable display device and is bent to be in contact with the topface of the upper potion during the out-folding operation.

In one implementation of the first aspect, the foldable display devicefurther comprises a hinge connecting the first casing and the secondcasing to each other, wherein the hinge includes: a pair of hinge shaftsrespectively coupled to the first casing and the second casing; and apair of gears rotatably and respectively coupled to the pair of hingeshafts.

In one implementation of the first aspect, a driving gear of the threedriving gears farthest from the support body is coupled to the hingeshaft and rotates under rotation of the hinge shaft.

In one implementation of the first aspect, one side wall of a lowerportion of the support is guided by one of the driving gears, while theopposite side wall of a lower portion of the support is guided by thehinge shaft.

In one implementation of the first aspect, the foldable display devicefurther comprises a support plate disposed between the display panel andthe first casing, and between the display panel and the second casing,wherein the support plate includes: a foldable portion corresponding tothe foldable area of the display panel and made of a combination of ametal material and a polymer material; and a first non-foldable portioncorresponding to the first area of the display panel and a secondnon-foldable portion corresponding to the second area of the displaypanel, and the first non-foldable portion and the second non-foldableportion are made of a metal material.

In one implementation of the first aspect, the foldable portion of thesupport plate is not attached to the foldable area of the display panel,while the first non-foldable portion of the support plate is attached tothe first area of the display panel and the second non-foldable portionof the support plate is attached to the second area of the displaypanel.

A second aspect of the present disclosure provides a foldable displaydevice comprising: a display panel having a foldable area; a firstcasing and a second casing to support the display panel, wherein thefirst casing and the second casing are coupled to each other via ahinge; a support coupled to the hinge to selectively support the displaypanel according to a folding direction of the foldable display device;and a hinge cover to accommodate therein the hinge and the support,wherein the support includes a support body, wherein the support bodyascends toward the display panel during an out-folding operation of thefoldable display device, and descends toward a bottom face of the hingecover during an in-folding operation of the foldable display device.

In one implementation of the second aspect, the support further includesthree driving gears rotating in engagement with each other to lift up orlower down the support, wherein the support body has a lower portion,wherein a rack gear is formed on one side wall of the lower portion andmeshes with one of the three driving gears.

In one implementation of the second aspect, the support body has a lowerportion and an upper portion having a greater width than a width of thelower portion, wherein the upper portion of the support has a top faceconvexly curved toward the display panel.

In one implementation of the second aspect, the support further includesan elastic plate partially coupled to the upper portion of the support,wherein a shape of the elastic plate varies based on a folded state ofthe foldable display device.

In one implementation of the second aspect, the hinge includes: a pairof hinge shafts respectively coupled to the first casing and the secondcasing; and a pair of gears rotatably and respectively coupled to thepair of hinge shafts.

In one implementation of the second aspect, a driving gear of the threedriving gears farthest from the support body is coupled to the hingeshaft and rotates under rotation of the hinge shaft.

In one implementation of the second aspect, one side wall of the lowerportion of the support is guided by one of the driving gears, while theopposite side wall of the lower portion of the support is guided by thehinge shaft.

A third aspect of the present disclosure provides a foldable displaydevice comprising: a first casing supporting a first area of a displaypanel; a second casing accommodating a slidable plate and including asliding-guiding groove to guide a slide movement of the slidable plate,wherein the slidable plate supports a second area of the display panel;a support disposed between the first casing and the second casing toselectively support the display panel according to a folding directionof the foldable display device; and a hinge cover to accommodate thesupport therein; wherein the support includes a support body, whereinthe support body ascends toward the display panel during an out-foldingoperation of the foldable display device, and descends toward a bottomface of the hinge cover during an in-folding operation of the foldabledisplay device.

Although the embodiments of the present disclosure have been describedin more detail with reference to the accompanying drawings, the presentdisclosure is not necessarily limited to these embodiments. The presentdisclosure can be implemented in various modified manners within thescope not departing from the technical idea of the present disclosure.Accordingly, the embodiments disclosed in the present disclosure are notintended to limit the technical idea of the present disclosure, but todescribe the present disclosure. the scope of the technical idea of thepresent disclosure is not limited by the embodiments. Therefore, itshould be understood that the embodiments as described above areillustrative and non-limiting in all respects. The scope of protectionof the present disclosure should be interpreted by the claims, and alltechnical ideas within the scope of the present disclosure should beinterpreted as being included in the scope of the present disclosure.

What is claimed is:
 1. A foldable display device, comprising: a displaypanel having a first area, a second area, and a foldable area betweenthe first area and the second area; a first casing supporting the firstarea of the display panel; a second casing supporting the second area ofthe display panel and being spaced from the first casing; a supportdisposed between the first casing and the second casing to support thedisplay panel; and a hinge cover accommodating the support, wherein thesupport includes a support body that is configured to ascend toward thedisplay panel during an out-folding operation of the foldable displaydevice, and descend toward a bottom face of the hinge cover during anin-folding operation of the foldable display device, wherein thefoldable display device further comprises a support plate, the supportplate including a foldable portion overlapping the foldable area of thedisplay panel and configured to fold in response to the out-foldingoperation and in response to the in-folding operation, wherein thefoldable portion includes a plurality of holes, and wherein an upperportion of the support body has a top face convexly curved toward thedisplay panel with a fixed curvature and has a greater width than thatof a lower portion of the support body including a rack gear.
 2. Thefoldable display device of claim 1, wherein the support further includesat least two driving gears rotating in engagement with each other tolift up or lower down the support body.
 3. The foldable display deviceof claim 2, wherein the rack gear meshes with a first gear among the atleast two driving gears.
 4. The foldable display device of claim 2,wherein the foldable display device further comprises a hinge connectingthe first casing to the second casing, and wherein the hinge includes: apair of hinge shafts respectively coupled to the first casing and thesecond casing; and a pair of hinge gears respectively rotatably coupledto the pair of hinge shafts.
 5. The foldable display device of claim 4,wherein the at least two driving gears includes three driving gears, andwherein a third driving gear among the three driving gears farthest fromthe support body is coupled to a first hinge shaft among the pair ofhinge shafts and is configured to rotate via rotation of the first hingeshaft.
 6. The foldable display device of claim 5, wherein a first sidewall of the lower portion of the support body is guided by a firstdriving gear among the three driving gears, and a second opposite sidewall of the lower portion of the support body opposite to the first sidewall of the lower portion of the support body is guided by a secondhinge shaft among the pair of hinge shafts.
 7. The foldable displaydevice of claim 1, wherein the support further includes an elastic platepartially coupled to the upper portion of the support, and wherein theelastic plate is configured to have a flat shape in an unfolded state ofthe foldable display device and to have a bent shape conforming to theconvexly curved shape of the top face of the upper portion of thesupport in an out-folded state of the foldable display device.
 8. Thefoldable display device of claim 1, wherein the support plate isdisposed between the display panel and the first casing, and disposedbetween the display panel and the second casing, and wherein the supportplate further includes at least one non-foldable portion overlapping oneof the first area of the display panel and the second area of thedisplay panel.
 9. The foldable display device of claim 8, wherein the atleast one non-foldable portion of the support plate is attached to theone of the first area of the display panel and the second area of thedisplay panel, and the foldable portion of the support plate is notattached to the foldable area of the display panel.
 10. The foldabledisplay device of claim 1, further comprising a first pivoting platedisposed between the first casing and the display panel and configuredto pivot to support the foldable area of the display panel during theout-folding operation and the in-folding operation, wherein one end ofthe first pivoting plate is supported by the hinge cover.
 11. Thefoldable display device of claim 1, wherein the plurality of holes ofthe foldable portion are filled with a polymer.
 12. A foldable displaydevice, comprising: a display panel having a foldable area; a firstcasing supporting the display panel; a second casing supporting thedisplay panel and spaced from the first casing; a hinge coupling thefirst casing to the second casing; a support coupled to the hinge toselectively support the display panel and including a support bodyconfigured to ascend toward the display panel during an out-foldingoperation of the foldable display device, and descend away from thedisplay panel during an in-folding operation of the foldable display;and a support plate including a foldable portion overlapping thefoldable area of the display panel and configured to fold in response tothe out-folding operation and in response to the in-folding operation,wherein the foldable portion includes a plurality of holes, and whereinan upper portion of the support body has a top face convexly curvedtoward the display panel with a fixed curvature and has a greater widththan that of a lower portion of the support body including a rack gear.13. The foldable display device of claim 12, further comprising: a hingecover covering the support; and a first pivoting plate disposed betweenthe first casing and the display panel and configured to pivot tosupport the foldable area of the display panel during the out-foldingoperation and the in-folding operation, wherein one end of the firstpivoting plate is supported by the hinge cover.
 14. The foldable displaydevice of claim 13, further comprising a second pivoting plate disposedbetween the second casing and the display panel and configured to pivotto support the foldable area of the display panel during the out-foldingoperation and the in-folding operation, wherein the first pivoting plateis disposed laterally between the support body and the first casing, andwherein the second pivoting plate is disposed laterally between thesupport body and the second casing.
 15. The foldable display device ofclaim 12, wherein the support further includes: at least two drivinggears rotating in engagement with each other to lift up or lower downthe support body, and wherein the rack gear is configured to mesh with afirst gear among the at least two driving gears.
 16. The foldabledisplay device of claim 15, wherein the hinge includes: a pair of hingeshafts respectively coupled to the first casing and the second casing;and a pair of hinge gears respectively rotatably coupled to the pair ofhinge shafts.
 17. The foldable display device of claim 16, wherein theat least two driving gears includes three driving gears, and wherein athird driving gear among the three driving gears farthest from thesupport body is coupled to a first hinge shaft among the pair of hingeshafts and is configured to rotate via rotation of the first hingeshaft.
 18. The foldable display device of claim 17, wherein a first sidewall of the lower portion of the support body is guided by a firstdriving gear among the three driving gears and a second side wall of thelower portion of the support body opposite to the first side wall of thelower portion of the support body is guided by a second hinge shaftamong the pair of hinge shafts.
 19. The foldable display device of claim12, wherein the support further includes an elastic plate partiallycoupled to the upper portion of the support, and wherein a shape of theelastic plate changes between an unfolded state of the foldable displaydevice, the out-folding operation of the foldable display device, andthe in-folding operation of the foldable display.
 20. A foldable displaydevice, comprising: a display panel; a first casing supporting a firstarea of the display panel; a second casing accommodating at least oneslidable plate and including at least one sliding-guiding groove toguide a slide movement of the at least one slidable plate in a firstdirection, wherein the at least one slidable plate supports a secondarea of the display panel spaced from the first area of the displaypanel; a support disposed between the first casing and the second casingto support the display panel and including a support body configured toascend in a second direction toward the display panel during anout-folding operation of the foldable display device, and descend in thesecond direction away from the display panel during an in-foldingoperation of the foldable display, the second direction beingsubstantially perpendicular to the first direction; and a support plateincluding a foldable portion overlapping the foldable area of thedisplay panel and configured to fold in response to the out-foldingoperation and in response to the in-folding operation, wherein thefoldable portion includes a plurality of holes, and wherein an upperportion of the support body has a top face convexly curved toward thedisplay panel with a fixed curvature and has a greater width than thatof a lower portion of the support body including a rack gear.
 21. Thefoldable display device of claim 20, further comprising: a hinge covercovering the support; and a first pivoting plate disposed between thefirst casing and the display panel and configured to pivot to supportthe foldable area of the display panel during the out-folding operationand the in-folding operation, wherein one end of the first pivotingplate is supported by the hinge cover.